flutter vi. 1.拍翅振翼;(旗幟)飄揚。 2.顫動,(心)急跳,(脈搏)浮動。 3.(心緒)不寧,坐立不安。 4.〔口語〕對人進行測謊。 He fluttered about the room nervously. 他心緒不寧地在房間里徘回。 vt. 1.振(翼);拍(翅)。 2.擾亂;使不安。 n. 1.振翼;飄揚。 2.不安,焦急,波動。 3.(身體部分的)病態陣跳。 4.〔英俚〕投機,小賭。 5.顫振。 6.圖像跳動,脈沖干擾,放音失真。 7.對…進行測謊。 the flutter of wings 翅膀的拍動。 all in a flutter 心慌意亂。 cause [make] a great flutter 轟動一時。 fall into a flutter 心慌意亂。 in a flutter 心里卜卜跳。 put sb. in [into] a flutter = throw sb. into a flutter 使忐忑不安。 n. -er ,-ingly adv.
Simulations for identification of flutter derivatives of bridge section using the coupled - forced - vibration method 橋梁顫振導數的耦合強迫振動仿真識別
A comparative study between time - domain method and frequency - domain method for identification of bridge flutter derivatives 橋梁顫振導數識別的時域法與頻域法對比研究
The researcher also concludes that in the range of reduced velocity , the flutter derivatives equal to the function of it 在折減風速的實用范圍之內,顫振導數只是折減風速的函數。
The identification of flutter derivatives for bridge sectional model has long been a key issue in long - span bridge flutter and buffeting analysis 長期以來,橋梁斷面顫振導數的識別都是大跨度橋梁顫抖振響應分析中的重點和難點問題。
And the result shows that the self - excited loads and the flutter derivatives satisfying the linear relationship as to the streamline section - like thin plate 結果表明對薄平板這一類近乎流線體的斷面,自激力與振動參數之間能較好地滿足線性關系。
2 . a systematic test has been carried out to observe how the model actuating frequencies and amplitudes affect the flutter derivatives , and the effect is found to be quite minor 通過系列試驗考查了模型驅動頻率和振幅對顫振導數的影響,驗證了驅動頻率和振幅對顫振導數影響很小。
While the flutter self - excited loads of a bluff section has a quality of obvious nonlinearity . and the application of flutter derivatives to self - excited loads of the bluff section is close to a linear relationship . 5 而鈍體斷面的顫振自激力高次諧波分量較大,具有較明顯的非線性響應特征,驗證了用顫振導數表示鈍體的自激力只是一種線性近似。
A test has been carried out on three typical bridges sectional models of flutter derivatives to find the general rules with the change of flutter derivatives of the bridges sectional model . and it has been discovered that this change depend on the torsional damping , an element closely relating to the h * 2 and a * 2 4 通過對三種典型斷面顫振導數的測試,考查了各顫振導數隨斷面形狀的變化趨勢,說明了最主要的變化體現在與扭轉阻尼有關的h _ 2和a _ 2項。
The result of the experiment shows that the proposed forced vibration method device has the quality of stability and repetitiveness of the data , the wide range of the testable reduced velocity , the exactness of coupled and direct flutter derivatives . and it does not need to employ any complicated identification system to check it further 結果顯示:本文提出的強迫振動法裝置具有試驗數據穩定、數據重復性好、可測量的折減風速范圍寬、交叉項導數與對角項導數具有同等精度和不需要復雜的系統識別過程等一系列優點。
As to the current problems existing in the identification for these flutter derivatives , the dissertation tries to trace the development in the identification for the past unsteady aerodynamic forces of long - span bridges . it also investigates the method for flutter and buffeting analysis and the flutter derivatives . based on the present methods used in obtaining the unsteady aerodynamic forces and flutter derivatives , and co - funded by a natural scientific fund from the nation and a key project fund from the railway ministry , the current research has attempted to develop a device which can be employed in the wind tunnel to test flutter derivative through a forced vibration method 鑒于目前橋梁斷面顫振導數識別的水平和存在的問題,本文通過對大跨度橋梁非定常氣動力、顫振分析方法及顫振導數識別方法的回顧和評述,基于現有的非定常氣動力和顫振導數的測試方法,在國家自然科學基金與鐵道部重點學科基金的聯合資助下,研究開發了一套在風洞中采用強迫振動法測試顫振導數的裝置。